The invention relates generally to milling apparatus and, more specifically, to a cheek plate which uses compressed air to direct material being milled between a pair of milling rollers.
Conventional milling apparatus use a pair of milling rollers positioned closely adjacent and rotated in opposite directions so that material to be milled passes generally between the rollers. The position of the rollers is relatively moveable to permit adjustment of the milling distance between the rollers to affect the characteristics of the milled product and to accommodate a diversity of materials.
In conventional milling apparatus, cheek plates are used at either end of the pair of rollers to prevent material from flowing or passing over the ends of the rollers and thereby not being milled. Known cheek plates must be carefully positioned closely adjacent or in sliding contact engagement with the pair of rollers. Unless the cheek plates are appropriately positioned, material being milled will become lodged between the cheek plates and the rollers, causing excessive wear to the cheek plates and loss of efficiency of the milling operation, or may work underneath and past the cheek plates where it will fall unmilled into otherwise milled material below. Unmilled material will detract from the uniformity of the desired milled material and may cause problems in certain of the after-processing uses of the milled material.
To avoid such problems, it is necessary to monitor and maintain the position of the cheek plates flush with the rollers. During operation of the milling apparatus, the conventional cheek plates wear and abrade with the result that a gap may exist between the rollers and the cheek plate which will enlarge and eventually allow the material to pass unmilled over the ends of the rollers. As the cheek plates wear, accordingly, they must be moved regularly to be maintained in flush contact with the rollers. After some period of time, the cheek plates will have worn to the point where they must be replaced.
There is a need, therefore, for a cheek plate which will direct material between the rollers and prevent it from passing unmilled over the ends of the rollers and which is not in need of constant adjustment and will not require frequent replacement.